The subject matter herein relates generally to electrical connector systems.
Some electrical systems utilize electrical connectors to interconnect two circuit boards, such as a motherboard and daughtercard. Signal loss and/or signal degradation is a problem in known electrical systems. For example, cross talk results from an electromagnetic coupling of the fields surrounding an active conductor or differential pair of conductors and an adjacent conductor or differential pair of conductors. The strength of the coupling generally depends on the separation between the conductors, thus, cross talk may be significant when the electrical connectors are placed in close proximity to each other. The strength of the coupling also depends on the material separating the conductors. Moreover, as speed and performance demands increase, known electrical connectors are proving to be insufficient. Additionally, there is a desire to increase the density of electrical connectors to increase throughput of the electrical system, without an appreciable increase in size of the electrical connectors, and in some cases, with a decrease in size of the electrical connectors. Such increase in density and/or reduction in size causes further strains on performance.
In order to address performance, some electrical connectors have been developed that utilize shielded contact modules that are stacked into a housing. The shielded contact modules have conductive holders that provide shielding around the contacts of the electrical connectors. However, in some eases, when the electrical connectors are mated, full mating does not occur, leaving an air gap between the connectors. Such air gap has a dielectric constant that is different than the dielectric constant of the material designed to surround the conductors, thus affecting the impedance of the conductors.
A need remains for electrical connectors having improved impedance control to increase the electrical performance thereof.